another good reason to own an old rocky - mpg


Hi all, would like some feedback on this if you want, i have had to change my fuel tank due to a pepperpot - no probs, but by doing so i have drained my fuel tank a couple of times, i made a note of how much fuel i had got, i was pretty maticulous about this as i am always interested in my mpg,i have always guessed it has done around the 35-40 mpg mark, i measured it, put it back, tripped my milometer, and over a couple of days doing various journeys at about 40mph on 31-10.5 r15 tyres i recorded (using a gallon at 4.5 litres) that my f70 does a lovely 37.5 mpg, not bad for a twenty year old 2.8 tdi thats done 183000 miles - very happy with that!! Smile


'91 Fourtrak 2,8 TDX

What have you found re Motorway driving, thinking that the turbo kicks in around 2200revs, approx 55mph in 5th gear ( (31-10.50r15 tyres), and she's about as streamlined as a brick.

I agree with local pottering about she seems quite frugal, but cross that threshold when the turbo kicks in and your keeping up with the traffic or more ,the fuel gauge falls like a stone. Doing the same journey, mainly motorway and some single carriageway driving , keeping at 2200 rpm (50/55mph) on the motorway does make a considerable difference to fuel use, than to when I put the pedal to the metal, hell I give her the boot on the outward trip and come home more sedatly, and do I notice the difference. Thankfully I have never worried about fuel consumpsion, but when its cost effectice I do mix with new rapeseed oil, as of the moment, ex supermarket new rapeseed oil localy is 10 pence cheaper than diesel per litre.

I respect she was never built as a motorway cruiser, just a general workhorse and a damned good one, with an engine that was built to take allsorts of quality of diesel fuel where ever in the world. I imagine that high speed motoring was the last thing that the designers of the Fourtrak thought the the truck would be used for, and she is used for offroading.

Edward (ews) '92 Fourtrak 2.8 TDX


I never take to the motorway or hardly even a dual carriageway with it, it only ever really sees country roads, but when i did use the vehicle the other year for a caravan trip i think it roughly worked out at 30 mpg, but that wasnt accurate compared to what ive done here, sorry.

Full of ideas but no time to do them!!
youtube: Redfourtrack

Economy or Not

Fuel efficiency is determined in many ways, the main one being the way a vehicle is driven, followed by the conditions it is driven under.

MPG is fine if you do mainly road work, but off road is a different matter, this is usually gallons per hour GPH, or litres per hour LPH. During my time with the mining industry we had Defenders, being LR they were expected to work off road for weeks at a time, when the industry decided to introduce competition it was Fourtraks. During normal working conditions the vehicles were no different apart from the Fourtrak requiring a different driving style, and it was equally capable off road as a defender.

What really impressed was the operating costs, the LR were notoriously unreliable and thirsty using an average 8 GPH compared to the 5.5GPH of the Fourtrak. Considering the Fourtrak engine was designed in the 50's and the Defender engine some 30 years later it highlights the original engines merits. Servicing costs for the Fourtrak were considerably less, combined with their reliability ensured they became a firm favourite as they handled better on road, and were far more comfortable. We modified these vehicles extensively, additional lighting, full heavy underbody protection, and many more mods putting more load on the engine had negliable results on the fuel consumption. Put any weight on a LR and it reflected substantially in the increased fuel consumption.